METHOD FOR REMOVAL OF HARD COATING FILM IN SUPERHARD MATERIAL, AND METHOD FOR PRODUCTION OF SUPERHARD MATERIAL

摘要

Disclosed is a method for removing a hard coating film in a superhard material, which can selectively remove a hard coating film provided on the surface of a superhard material such as a superhard tool and a mold, and can minimize the deterioration in a superhard base material. Specifically disclosed is a method for removing a hard coating film in a superhard material in which the surface of a superhard base material is coated with the hard coating film, wherein the superhard base material is produced by sintering superhard alloy particles each comprising a carbide of at least one element selected from the group consisting of Group-4 elements, Group-5 elements and Group-6 elements with a binder metal comprising at least one element selected from the group consisting of Fe, Co, Cu and Ni or an alloy containing any one element selected from the preceding group, and wherein the hard coating film comprises a nitride, a carbide, a carbonitride, an oxide or a boride of at least one element selected from the group consisting of Group-4 elements, Group-5 elements, Group-6 elements, Group-13 elements and Group-14 elements (excluding carbon). The method comprises bringing the superhard material into contact with an alkaline solution at a temperature ranging from 100 to 250°C inclusive.